The present invention relates to shelf support members for supporting the shelves in a refrigerator having an internal sheet metal wall and for joining two or more thin sheet metal panels.
At the present time refrigerators are manufactured with various types of internal walls, i.e., liners. The internal wall of the refrigerator is separated from the exterior wall by insulation, for example, of foamed plastic such as foam polystyrene or foam polyurethane. It is generally desired that the shelves in the refrigerator, used to support the foodstuffs within the refrigerator, are not permanently attached to the internal side walls of the refrigerator but may be moved from one level to another. This enables the user to vary the shelf heights and distances between shelves to accord with the height of the bottles or other foodstuffs within the refrigerator. For example, the shelves may be temporarily removed so that the refrigerator will accommodate a large turkey or a large pot or the shelves may be moved upwardly or downwardly to accommodate tall bottles.
There have been many proposals for various types of shelf support members. For example, if the internal walls of the refrigerator are of molded plastic, it is possible to mold extending tabs as integral parts of the internal refrigerator side walls. These tabs may then serve as the shelf supports. However, if the internal side wall of the refrigerator is of sheet metal, it is not possible to integrally mold the shelf support as part of the wall. Rather, the shelf support members must be separate members which are fastened to the wall.
To provide flexibility of shelf arrangements, it is known to use a large number of shelf support members which are knobs or other shapes of protruding members and which are fastened in place by being secured through the internal wall of the refrigerator. The fastening of such shelf support members to the internal wall of a refrigerator when the internal wall is of sheet metal presents various problems. One problem arises because it is essential that the shelf support member be firmly fixed in position. It is an accepted industry standard that each individual shelf support member should support a minimum of 50 pounds. A further problem arises because it is a further requirement that the shelf support member not become loosened with the passage of time, for example, after it has received a considerable number of sideways forces due to the insertion and removal of the shelves as well as occasional bumps received when bottles and other food containers are removed or inserted into the refrigerator. It is still a further requirement that the part not deteriorate in usage or become discolored.
Some of the shelf support members which have been proposed meet these various requirements and some of them have been used in the past. However, there has been a constant demand that the shelf support members should be low in price and should be readily fastened to the refrigerator wall. Both of these requirements relate to the overall cost of inserting a set of shelf support members in a refrigerator. With the ravages of inflation and the cost-consciousness of consumers in purchasing large household appliances such as refrigerators and freezers, the engineers and purchasing agents of refrigerator manufacturers have been very conscious of the total cost of furnishing a refrigerator with shelf supporting members and they have sought means to lower such costs. The problem of securing a shelf support member in a sheet metal panel is particularly acute if the sheet metal panel is thin, as a thin panel may provide less frictional engagement to hold the shelf support member.
Consequently, it is an objective of the present invention to provide a shelf support member which will be low in cost and which will be self-piercing so as not to require drilling or otherwise forming holes in the refrigerator liner before insertion of the shelf support member.
It is a further objective of the present invention to provide such a shelf support member which is adapted for the automatic piercing of the internal wall of the refrigerator by machine.
It is a further objective of the present invention to provide such a shelf support member which will firmly support a shelf of a refrigerator and meet the standard of supporting at least 50 pounds placed on each individual shelf support member and further which will retain its ability to support that load over a long period of time without becoming loosened in its hole.
It is a further objective of the present invention to provide a "blind rivet" type of fastener which is utilized to join together two thin panels, for example, two thin sheet metal panels, by inserting the fastener through both panels from one side of one of the panels, without the necessity of forming holes in both panels prior to their being joined together. Alternatively, the panel next to the shelf support member may have a pre-formed hole or both panels may have pre-formed holes.
Other objectives of the present invention will be apparent from the following detailed description which provides the inventor's best mode of practicing the present invention.